Enable multinode grenade gate for Linuxbridge

[Ihar Hrachyshka]

OVS is covered in gate, we should do the same for Linuxbridge.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/345487

[OpenStack Infra (hudson-openstack)]

Change abandoned by Ihar Hrachyshka (<email address hidden>) on branch: stable/mitaka
Review: https://review.openstack.org/345487
Reason: For now.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/345428
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=d352661c56d5f03713e615b7e0c2c9c8688e0132
Submitter: Jenkins
Branch: master

commit d352661c56d5f03713e615b7e0c2c9c8688e0132
Author: Ihar Hrachyshka <email address hidden>
Date: Thu Jul 21 16:17:09 2016 +0200

    Revert "lb-agent: ensure tap mtu is the same as physical device"

    This reverts commit 6cf92011143eb55adda180ffac91886566fc7826.

    Conflicts:
     neutron/plugins/linuxbridge/agent/linuxbridge_neutron_agent.py
     neutron/tests/unit/plugins/linuxbridge/agent/test_linuxbridge_neutron_agent.py

    This hack was used to copy MTU from physical bridges to tap devices to
    support Jumbo frames. Now that we have proper MTU behaviour in interface
    drivers, this is not needed.

    This hack makes all efforts of the interface driver to set the correct
    network MTU on all ports ineffective. It breaks multinode grenade
    linuxbridge job, among other things.

    Even back in Liberty times when it was introduced, there was no real
    need to explicitly set Jumbo aware MTU on tap devices from Neutron side.
    This could have been achieved by setting network_device_mtu on Nova side
    in addition to Neutron:

    https://github.com/openstack/nova/blob/liberty-eol/nova/network/linux_net.py#L1590

    Change-Id: I53c0eb57da956b36f09731d25db989719e9bc9dc
    Related-Bug: #1605271

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Bug closed due to lack of activity, please feel free to reopen if needed.